Jacket structure for offshore constructions

ABSTRACT

Jacket structure for offshore constructions, particularly jacket structure for offshore wind turbines, including a number of first and second profiles, whereby the first profiles include rods in axial alignment and the second profiles include rods in an angled alignment relative to the first profiles, and a number of node members providing a connection site for the second profiles, wherein the node members are connected to the first profiles and/or at least one adapter profile connected to at least one first profile of the jacket structure via a bolted connection.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the US National Stage of International ApplicationNo. PCT/EP2010/063546, filed Sep. 15, 2010 and claims the benefitthereof. The International Application claims the benefits of Europeanapplication No. 10163754.4 filed May 25, 2010. All of the applicationsare incorporated by reference herein in their entirety.

FIELD OF INVENTION

The invention relates to a jacket structure for offshore constructions,particularly a jacket structure for offshore wind turbines, comprising anumber of profiles in axial or angled alignment and a number of nodemembers.

BACKGROUND OF INVENTION

Offshore constructions for structures to be installed in the sea areusually necessary in particular for offshore wind power plants, that isoffshore wind turbines and represent a constructive challenge as therespective structure has to be erected on the seabed by means of anappropriate foundation.

A number of different types of foundations such as monopole-, tripile-,tripod- or gravity-foundations are known from prior art.

Aside, jacket structures are well-known since they are constructivelysimple, show good mechanical properties, particularly due to a highstiffness-to-material-use ratio, and thus, are adapted to be erected onsites with high wave-loads. Besides, jacket structures are comparativelycost-effective.

EP 2 067 914 A1 discloses a jacket structure comprising a number ofrod-profiles in axial or angled alignment and a number of node members,whereby a connection of the rod-profiles and the node members isachieved by welding.

SUMMARY OF INVENTION

Yet, welding represents a comparatively complex connecting method forestablishing a stable connection of the node members with respectiveparts of the jacket structure, that is foremost the profiles of thejacket structure. Accordingly, the used materials must be weldable,which is deemed as a restriction in the selection of possible materialsfor the jacket structure. Altogether, welded joints are fairly complexin planning and realisation.

Hence, it is the object of the invention to provide a jacket structurefor offshore constructions with an improved connecting principleconcerning the node members.

This is achieved by a jacket structure for offshore constructions asdescribed above, wherein the node members are connected to the jacketstructure and/or at least one adapter profile connected to at least onefirst profile of the jacket structure by means of a bolted connection.

Hence, the present invention uses bolted joints instead of welded jointsfor providing a connection of the node members with respective firstprofiles of the jacket structure, that is respective axially extendingrods and/or the at least one adapter profile connected to at least onefirst profile of the jacket structure. Bolted-connections are detachableand generally represent a constructively simple and quick way to providea mechanically stable connection or installation of the jacket structureas a whole. As a result, the jacket structure may be easily and fasterected on a respective site. The bolted connections may be improved bythe use of threads provided with the connected parts so that connectingmeans such as bolts or the like may be more stably engaged.

Additionally or alternatively, it is possible that the jacket structurecomprises at least one adapter profile connected to at least one firstprofile of the jacket structure, whereby at least one node member isconnected to the adapter profile. In such a manner, the adapter profileand the node member preferably built a pre-assembled component,comprising a bolted connection of the node member with the adapterprofile. Hence, the adapter profile may be deemed as a separate partwhich serves to establish a connection between the node member and atleast one first profile of the jacket structure.

Consequently, the adapter profile comprises at least two differentconnection portions, that is one for connecting with the node member bymeans of the inventive bolted joint and at least a second one forconnecting with an adjacently axially disposed first profile of thejacket structure, whereby in the latter case not only bolted connectionsmay be used, but different types of connections such as welded jointsfor instance are applicable as well.

In such a manner, the inventive jacket structure is easy to mantle, thatis can be mantled “on site”. Likewise, load calculations are reduced incomplexity as well as costly inspections of welded joints are notnecessary with the inventive jacket structure providing an easy,cost-effective connecting principle. Further, the inventive jacketstructure allows a high degree of flexibility concerning diameters, wallthicknesses, angles, etc. of the respective profiles and/or nodemembers.

The first and second profiles of the jacket structure are usually atleast partially hollow or massive rods. The cross-section of the firstand second profiles and the node members respectively is preferablyround or elliptical, yet other shapes are feasible as well. All parts ofthe jacket structure are built of materials which are capable for theuse in offshore-applications and particularly comprise good mechanicaland anti-corrosive properties. An appropriate material may be stainlesssteel for instance. Anti-corrosive coatings or varnishes may be appliedto the surface of the parts of the jacket structure.

Preferably, the node member comprises a base plate and at least oneconnecting member extending off the base plate for connecting with asecond profile.

Hence, the node member essentially comprises two different connectingportions, whereby the base plate is related to the axial first profilesor the adapter profile respectively and the connecting member is relatedto a respective angled second profile. The base plate and the connectingmember are stably, preferably non-detachably connected with each other.Thus, the base plate and the connecting member may be integrally formedor represent separate stably joint components, whereby a firm connectionmay be attained by welding or the like for instance.

In a further embodiment of the invention the base plate comprises aconnecting portion for connecting the node member with a first profileor the adapter profile. In such a manner, a defined connection of thenode member and a first profile or an adapter profile of the jacketstructure is attainable by means of the connecting portion which isallocated to the base plate of the node member.

Thereby, it is preferred that the connecting portion of the node membercomprises a number of bores, whereby bolts penetrate through the boresthereby, connecting the node member to the first profile or the adapterprofile. Thus, a bolted connection of the node member is achievable bybolts engaging through the bores or through holes disposed within thebase plate and further into corresponding connecting portions providedwith the first profiles or adapter profiles respectively. Threads may beapplicable, that is bores and bolts may be provided with correspondingthreads at their respective diameters which increases the strength ofthe bolted joint.

The bores are favourably circumferentially disposed at the borders ofthe base plate. This arrangement of the bores provides a good stabilityof the inventive bolted connection. However, the bores may additionallyor alternatively be disposed at different sites of the base plate inexceptional cases. The concrete number and arrangement of the bores maydiffer and depends mainly on the constructive design and load of theinventive jacket structure.

It is possible, that at least one additional connecting member extendsoff the connecting member. Thereby, the number of potentiallyconnectable second profiles to be connected with the node member may beincreased by means of a branched structure of the connecting member. Itis understood, that the joint between the connecting member and therespective at least one further connecting member branching thereof ismechanically stable, whereby preferably an integral design of theconnecting member with the respective further connecting members is infavour. Thereby, welded joints or the like are applicable for instance.

Aside, the invention relates to a node arrangement for a jacketstructure as described before comprising at least one node member beingconnected to an adapter profile by means of a bolted connection, wherebythe adapter profile is connectable or connected to a first profile ofthe jacket structure. The node arrangement essentially represents acomponent that is ready to be connected with first profiles of thejacket structure by means of the adapter profile and further, secondprofiles of the jacket structure by means of the node member as will bedescribed later on. The bolted connection between the node member andthe adapter profile contributes to a fast and firm connection of thenode member with the adapter profile.

The node member preferably comprises a base plate and at least oneconnecting member extending off the base plate. Thereby, the connectingmember may provide a connection with a second profile that is a rod inan angled alignment with respect to the axial alignment of the firstprofiles. In other words, the base plate is related to axial extendingprofiles and the connecting member is related to angled extendingprofiles of the jacket structure.

It is preferred, when the base plate comprises a connecting portion. Theconnecting portion is adapted to provide a proper connection of the baseplate with the adapter profile.

In such a manner, the connecting portion may comprise a number of bores,whereby each bore is adapted to accommodate a bolt. Thus, the connectionof the base plate of the node member and the adapter profile may beattained by bolts penetrating through the bores into appropriateconnecting portions of the adapter profile. If need be, the bores andbolts may be provided with corresponding threads.

The bores are preferably circumferentially disposed at the boarders ofthe base plate. Of course, other arrangements of the bores areapplicable as well.

Further, it is possible that at least one additional connecting memberextends off the connecting member. In such a manner, the number ofpossibly attached second profiles may be increased with respect to asingle node arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention is described in detail as reference ismade of the figures, whereby

FIG. 1 shows a principle cut-out view of a jacket structure according toa first exemplary embodiment of the invention;

FIG. 2 shows a principle cut-out view of a node arrangement according toa second exemplary embodiment of the invention;

FIG. 3 shows a principle cut-out view of a node arrangement according toa third exemplary embodiment of the invention;

FIG. 4 shows a principle cut-out view of a node arrangement according toa fourth exemplary embodiment of the invention; and

FIG. 5 shows a principle cut-out view of a jacket structure according toa second exemplary embodiment of the invention.

DETAILED DESCRIPTION OF INVENTION

FIG. 1 shows a principle cut-out view of a jacket structure 1 accordingto a first exemplary embodiment of the invention, whereby only essentialparts are depicted, that is FIG. 1 contains only a representative partof the inventive jacket structure 1. The jacket structure 1 comprisesfirst and second profiles 2, 3 (dotted) in the shape of axial extendingsteel rods (first profile 2) and in the shape of steel rods in an angledalignment (second profile 3) relative to a first profile 2. The jacketstructure 1 further comprises a number of node members 4 in a regulararrangement, whereby FIG. 1 shows only one representative example. Thejacket structure 1 is preferably used for offshore wind turbines.

As is discernible from FIG. 1, the node members 4 provide a connectionsite for the second profiles 3 by means of the connecting member 5extending off the base plate 6 both representing the essential parts ofthe node member 4. The node member 4 comprises a respective connectingportion in the shape of circumferentially distributed bores 7 providedwith the base plate 6. Bolts 8 engage through the bores 7 so as toengage in respective openings of an axially extending adapter profile 9.Hence, the node member 4, that is the base plate 6 and the adapterprofile 9 may be deemed as a pre-assembled component in terms of a nodearrangement 10 (cf. FIGS. 2-4).

By means of the inventive bolted connection a simple and fast way todetach or attach the node member 4 to the adapter profile 9 of thejacket structure 1 is achievable, which is particularly of advantage interms of service and/or repair of the jacket structure 1 or respectiveparts of it.

FIG. 2 shows an inventive node arrangement 10 according to an exemplaryembodiment of the invention. The essential difference of the nodearrangement shown in FIG. 2 to the node arrangement shown in FIG. 1 isin that the node member 4 comprises two separate connecting members 5pointing in different, that is essentially opposite directions. In sucha manner, the node arrangement 10 or the node member 4 respectively maybe connected with two second profiles 3 of the jacket structure 1.

An alternative embodiment of an inventive node arrangement 10 accordingto a further exemplary embodiment of the invention is shown in FIG. 3.In this case, the node arrangement 10 comprises a branched connectingmember 5, that is an additional connecting member 11 extends off theconnecting member 5. Hence, the connecting member 5 subdivides intofurther connecting members, that is with respect to the presentembodiment the further connecting member 11. Of course, furtherconnecting members 11 may extend off the connecting member 5. It isunderstood, that further connecting members may also extend of theconnecting member 11. In such a manner, the number of possiblearrangements of second profiles 3 to the node arrangement 10, that isthe connecting members 5, 11 may be increased.

FIG. 4 shows a third embodiment of an inventive node arrangement 10,which is characterized in that the adapter profile 9 is connected withtwo separate node members 4 as they are depicted in FIG. 1.

In such a manner, the node arrangement 10 may also be connected with twoseparate second profiles 3 of the inventive jacket structure 1, wherebyin the embodiment according to FIG. 4 each node member 4 may beseparately connected with a respective second profile 3 (not shown) bymeans of the respective connecting members 5.

All node arrangements 10, that is the ones depicted in FIGS. 1 to 4comprise axial connecting portions 12 disposed at the free axial endingsof the adapter profile 9, so that the adapter profile 9 and the nodearrangement 10 as a whole may be connected to adjacently disposed firstprofiles 2 of the jacket structure 1 (not shown) by means of welded orbolted joints for instance.

FIG. 5 shows a jacket structure 1 according to a second embodiment ofthe invention. In this case, the node member 4 is directly joint to afirst profile 2 of the jacket structure 1 by means of a boltedconnection, that is bolts 8 penetrate through the bores 7 of the baseplate 6 of the node member 4 into corresponding openings within thefirst profile 2. Hence, the embodiment according to FIG. 5 represents abasic principle of the present invention, whereby a bolted connectionprovides a detachable, yet mechanically stable connection of a nodemember 4 with the jacket structure 1, that is a first profile 2 of thejacket structure 1.

1-13. (canceled)
 14. A node arrangement for a jacket structure having afirst profile and a second profile, comprising: a node member adapted tobe connected via a bolted connection to the first profile of the jacketand/or to an adapter profile of the jacket, the node member furtheradapted to provide a connection site for a second profile of the jacket.15. The node arrangement according to claim 14, wherein the node membercomprises a base plate, and wherein a connecting member extends off thebase plate to provide the connections site for the second profile 16.The node arrangement according to claim 15, wherein the base platecomprises a connecting portion for the bolted connection to the firstprofile and/or adapter profile.
 17. The node arrangement according toclaim 16, wherein the connecting portion comprises a plurality of bores,and wherein each bore is adapted to accommodate a bolt.
 18. The nodearrangement according to claim 17, wherein the bores arecircumferentially disposed at the boarders of the base plate.
 19. Thenode arrangement according to claim 14, wherein an additional connectingmember extends off the connecting member.
 20. A jacket structure foroffshore wind turbines, comprising: a first profile shaped as a rod inaxial alignment; a second profile shaped as a rod in an angled alignmentrelative to the first profile; and the node member of the nodearrangement of claim 14 is connected via a bolted connection to thefirst profile and/or an adapter profile which is connected the firstprofile, the node member providing a connection site for the secondprofile.
 21. The jacket structure according to claim 20, the node memberof the node arrangement of claim 14 is connected via a bolted connectionto the first profile and/or an adapter profile which is connected thefirst profile, the node member providing a connection site for thesecond profile.
 22. The jacket structure according to claim 20, whereinthe adapter profile and the node member build a pre-assembled component.23. The jacket structure according to claim 22, wherein the node membercomprises a base plate and a connecting member for connecting with asecond profile extending off the base plate.
 24. The jacket structureaccording to claim 23, wherein the base plate comprises a connectingportion for connecting the node member with the first profile or withthe adapter profile.
 25. The jacket structure according to claim 24,wherein the connecting portion of the node member comprises a pluralityof bores, wherein bolts penetrate through the bores in order to connectthe node member to the first profile and/or the adapter profile.
 26. Thejacket structure according to claim 25, wherein the bores arecircumferentially disposed at the boarders of the base plate.
 27. Thejacket structure according to claim 20, wherein an additional connectingmember extends off the connecting member.